Blizzard has announced Real ID, which it calls a "completely voluntary and optional level of identity that will keep players connected across all of Battle.net." The first game to get support for Real ID will be World of Warcraft.
The idea is to give Battle.net users a way to connect with real friends using real names and give them a means to communicate and share independent of the Blizzard game they might be playing at the time. Your Real ID friends will appear under their "real-life names" on your friends list, when chatting, communicating in-game, or viewing a character's profile. Real ID friends can also see who's on each other's Real ID friends list, making it easy for players to connect with other people they might know.
For World of Warcraft players this allows for cross-realm and cross-game chat - for example, when you friend is play StarCraft 2 you can harass him or her while in World of Warcraft.. And when you "friend" someone once you will see all the characters they have created in Blizzard games to date. Apparently this will even include "future games" someone might be playing like betas and beta content.
Finally, Real ID will feature a parental control layer for those parents interested in using. Those that already use parental controls should be getting some details in their inboxes soon, but the short answer is that parents can decide if their children can participate in Real ID .. for obvious reasons.